1. Field of the Invention
This invention involves a novel polymeric dispersant and pigment dispersions and curable compositions incorporating the dispersant. The dispersant is especially adapted for dispersing pigments therein and it is compatible with a wide variety of film-forming polymers. Due to the unique composition and molecular weight distribution of the polymeric dispersants, they are especially suited for use in high solid coating compositions.
2. Description of the Prior Art
Polymeric dispersants have been known in the art. For example, U.S. Pat. No. 4,242,243 teaches high solids ambient curing coatings utilizing an acrylic/fatty acid drying oil resin as a polymeric dispersant. U.S. Pat. Nos. 4,302,560; 4,302,561; 4,302,562; 4,303,764; and 4,339,365 teach polymeric dispersants having acid groups and amine groups and a weight average molecular weight less than about 10,000. Ionic groups, such as acid or amine groups, can, in some situations, lead to undesirably high viscosities. Additionally, ionic groups can have adverse effects upon some aspects of coating performance by imparting water sensitivity to the dried or cured film. Ethylenic unsaturation can sometimes lead to poorer durability.